package com.leting.common.interceptor;

import java.io.OutputStream;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

public class UserInterceptor extends HandlerInterceptorAdapter {
	private static Logger logger = Logger.getLogger(UserInterceptor.class);

	/**
	 * 利用正则映射到需要拦截的路径
	 * 在业务处理器处理请求之前被调用 如果返回false 从当前的拦截器往回执行所有拦截器的afterCompletion(),再退出拦截器链
	 * 如果返回true 执行下一个拦截器,直到所有的拦截器都执行完毕 再执行被拦截的Controller 然后进入拦截器链,
	 * 从最后一个拦截器往回执行所有的postHandle() 接着再从最后一个拦截器往回执行所有的afterCompletion()
	 */
	@Override
	public boolean preHandle(HttpServletRequest request,
			HttpServletResponse response, Object handler) throws Exception {
		// logger.info("==============执行顺序: 1、preHandle================");
		String requestUri = request.getRequestURI();
		String contextPath = request.getContextPath();
		String url = requestUri.substring(contextPath.length());

		int uid = (int) request.getAttribute("uid");

		String jsoncallback = request.getParameter("jsoncallback");
		if (jsoncallback != null && !"".equals(jsoncallback)) {
			request.setAttribute("jsoncallback", jsoncallback);
		}
		logger.info("读取到操作用户的uid:"+uid);
		if (url != null&& url.startsWith("/user")) {
			if (uid==0) {//此时用户未登录
				response.setCharacterEncoding("UTF-8");
				response.setContentType("text/html;charset=utf-8");
				OutputStream outputStream = response.getOutputStream();
				String resStr = "{\"code\":401,\"msg\":\"Not logged in\"}";
				if (jsoncallback != null && !"".equals(jsoncallback)) {
					outputStream.write((jsoncallback + "(" + resStr + ")").getBytes());
				} else {
					outputStream.write(resStr.getBytes());
				}
				return false;
			}
		}
		return true;
	}

	/**
	 * 在业务处理器处理请求执行完成后,生成视图之前执行的动作 可在modelAndView中加入数据，比如当前时间
	 */
	@Override
	public void postHandle(HttpServletRequest request,
			HttpServletResponse response, Object handler,
			ModelAndView modelAndView) throws Exception {

		// logger.info("==============执行顺序: 2、postHandle================");
		if (modelAndView != null) { // 加入当前时间
			modelAndView.addObject("var", "测试postHandle");
		}
	}

	/**
	 * 在DispatcherServlet完全处理完请求后被调用,可用于清理资源等
	 * 
	 * 当有拦截器抛出异常时,会从当前拦截器往回执行所有的拦截器的afterCompletion()
	 */
	@Override
	public void afterCompletion(HttpServletRequest request,
			HttpServletResponse response, Object handler, Exception ex)
			throws Exception {
		// logger.info("==============执行顺序: 3、afterCompletion================");
	}
}
